Limit switch



Sept. 2, 17930. A, TER VEHN l 1,774,857-

LIMIT SWITCH Filed Sept. 28, 1927 mi! ll Il Il ll 7//////////////////gru/vanto@ Paiemedseptyz, 1930 i 'y I 01,774,857 l' UNITED STATES v f if ,ALBER'YEOTEa v'nnivyor 1 Y Application filed 'september 28, 1.927;,Seala-N l The present invention'relates to pumps for 43 which carries aspring contact 44,.v said dispensing oil7 gasoline and similar liquids,spring' contacting continuously with themey and particularly to pumps ofthe above char# tallic disc 40, as may beV clearly seen from" Y acterwhich are electrically actuated and in Figs. 1. and 2. :On'the saidinsulated support which the measurement'of the' liquid toghe disy42,Vthere is mounted a Contact carrier 45 tov pensed is effectedautomatically. More spewhich is'fiXed aspring contactblade46 which y ccifically, the invention resides in the provision may-'bepressedagainstthe surface of disc of an improved limit switch for automatically40 Vby a button l47, 'saidzblade being heldin f controlling the currentsupply, such switch' its tensioned or compressed position by means 10acting to' interrupt automatically,under pre:y of a' springcatch ordetent'49 carried" by a Q61).` determined conditions,the circuitwhereinthe brzi'cketz48 on-l the support 42. i Thedetentv motor thatdrives the pump is included; `49 is ,provided with aicut'awaypart'O aeriIn the accompanying drawing: v Initting-it to pass overthe disc i38andt0 be- Figure 1 is a front'view'of the improved engaged contiguous'ftothe 'said cut-away part v limitswitch; y bythestops39ffof discj38.M50-and 51 are Fig. 2 is a part-sectional side view thereof; theterminals correspondingto contacts "46 Figs. 3 and 4 are fragmentalvperspective and: 44, respectively, andrt'o 'which' terminals views, indiiferent positions, yof the springs areconnected, the wires!fl-leadiiig from Y which constitutethe electric contacts. i a suitablesourceQof current'(not shown) v y In the construction'illustrated,9indicates "Ilie apparatus furtherincludes a main 73' the operating shaftof the apparatus which switch-tof approved character for throwing isconnectedfto be driven from an` electric the entire apparatus intoineffective condin'iotorlnotshown) of` any lappro'ved'design tion, forinstance at night; and with the ar# and itself facts to drive the pumpproper rangement shown and described, it is evident f (alsounillustrated). y I that by acting on spring 46 by means 'of push- 75 Toeffect the starting and stoppingof the button 47, said spring, owing toitsresilience, motor, in order to actuate the pump and also will contactwith conducting disc 40, thereby"v 5 to adjust its workA in accordancewith pre-J closing` the motor circuit andv startingthe determinedquantities of liquid, the following operation ofthe pump. n

parts or devices are provided: To'the shaft Rotation of vshaft A9,'aswill be apparent, Si 9, 'there is secured a gear 36 which meshes ineects rotation of gem 37,2H1Cl the members a predetermined relation withanother gear secured to it and,-consequently,` at a certain f 37 fixedto a shaft 41; the ratio being in this movement, vone of the stops39vWll Strike vinstance 1:4, so that for each four complete against thelart 50 of the detent 49 (see y -stroles of thepump piston (which hasa.l Fig. 3) and eX the latterrightward so that 8,5 f driving connectionwith shaft 9), the gear 37 it willv be released from engagement with thewillmakeone complete revolution, Assum` free endv ofspring 46 which, dueto its re- Y ing that at each effective stroke of the piston silience,will then rassume theposition shown the volume of liquid drawn in isequivalent in Fig.` 4, 'separated from conducting disc to 5 liters, forinstance, one complete revo-1 40, thereby opening the circuit andcausing '90 lution of gear 37 Ywill correspond with the the motor tostop.The stop 39,as the counter` f vdischarge of" 20 liters. Gear 37yhas secured clockwise rotationof disc 38 continues, will e v v to itadisc 38 of insulating material, and ultimately pass by the part 50 ofthe detent at the centralpart of said disc there is se` to the otherside thereof,cthis taking place cured a metallic conducting disc 40. TleaboutV the same (crsubstantially the same) 9,5, insulating disc 38carries a set of stops 39, time that said detent is disengaged from aspaced at convenient intervals apart, say 90", spring 46. The apparatusis ready for a and arranged radially.V y further operation when the Fig.4 position `42 is avmember of insulating material and of the parts isassumed; the angular distance providing a support for the Contact memberbetween the stops 39 governing the number of `revolutions, of shaft 9and, accordingly, the

quantity of liquid discharged, since the latter is invariably the samefor each stroke of the pump. e,

I claim:

1. A limit switch for an electric circuit, embodying -a driveninsulatingdisc, a conducting disc fixed thereto, a set of' coacting flexiblecontacts, one of which is adapted to engage the vconducting disc andthereby complete thek circuit, means for holding said contact in suchengagement, and releasing means carried by therinsulating disc Vforterminating said engagement automatically. i 2. A switch according toclaim 1, in Which the vset of contactsjincludes a spring bladeconstantly engaging the conducting disc, and

ducting disc fixed thereto, a spring blade cona second blade normallyspaced fromsaid con'- ductingdisc but adapted to be moved into contacttherewith, and in which `the contact-hold ing means acts to hold thesecond blade incontacting position but is released by the releasingmeans on the insulating disc.

3. A limit switch forr an electric circuit, embodying y'a e driveninsulating disc, a constantlylengaging'the lconducting` disc, a secondblade normally spaced from said: conducting disc but adapted to be movedinto contact therewith,a spring detent'acting to engage the second bladeand hold itin contacting position, and aprojection on the insulatingdisc adapted to'A strike said detent and disengage it from the secondblade. i 1

` Y.ALBERTO TER VEHN.

